1. Field of the Invention
The present invention relates to a coating and developing system for coating a substrate, such as a semiconductor wafer or an LCD substrate, namely, a glass substrate for a liquid crystal display, with a resist solution by a coating process and processing the substrate by a developing process after exposure, a coating and developing method to be carried out by the coating and developing system, and a storage medium.
2. Description of the Related Art
A manufacturing process for manufacturing a semiconductor device or an LCD substrate forms a resist patter on a substrate by photolithography. Photolithography includes a series of steps of coating a surface of a substrate, such as a semiconductor wafer (hereinafter, referred to as “wafer”) with a resist film by applying a resist solution to the surface, exposing the resist film to light through a photomask, and processing the exposed resist film by a developing process to form a desired pattern.
Generally, those processes are carried out by a resist pattern forming system constructed by connecting an exposure system to a coating and developing system for coating a surface of a substrate with a resist solution and developing an exposed film. Such a resist pattern forming system is proposed in, for example, JP-A 2006-203075. In such a coating and developing system, an area in which modules for processing a substrate before the substrate is subjected to an exposure process, and an area in which modules for processing the substrate processed by the exposure system are vertically arranged in layers to further increase the processing rate of the coating and developing system, carrying devices are installed respectively in those areas to improve carrying efficiency by reducing load on the carrying devices so that the throughput of the coating and developing system may be increased.
Referring to FIG. 17, showing this known resist pattern forming system, a carrier block S1, a processing block S2 and an interface block arranged in that order are connected. The processing block S2 is built by stacking up developing blocks B1 and B2 for carrying out a developing process, a coating block B4 for carrying out a resist solution application process, and antireflection film forming blocks B3 and B5 for carrying out an antireflection film forming process before and after the resist solution application process. The blocks B1 to B5 of the processing block S2 are provided with wet-processing units for carrying out wet processes, such as the developing process, the resist solution application process and the chemical solution application process for applying a chemical solution for forming an antireflection film, shelf units formed by stacking up processing units for carrying out processes before and after the wet processes, carrying devices A1 to A5 for carrying wafers W to and from the modules of the wet-processing units and the shelf units, and exclusive transfer arms for transferring wafers W to and from the blocks B1 to B5.
A transfer arm C installed in the carrier block S1 carries a wafer W to the processing block S2, and the carrying devices A1 to A5 and transfer arms carry the wafer W to the desired processing units. Thus loads on the transfer arm C, the carrying devices A1 to A5, and the transfer arms are reduced to improve the throughput of the resist pattern forming system.
Although this resist pattern forming system can process wafers at a throughput on the order of, for example, 180 wafers/hr, the market demands for a system capable of processing wafers at a high throughput in the range of 200 to 250 wafers/hr. The inventors of the present invention have been engaged in developing a resist pattern forming system capable of achieving such a high throughput.
In this resist pattern forming system, each of the developing blocks B1 and B2 is provided with a developing unit formed by arranging, for example, three developing modules for carrying out the developing process. To achieve the developing process, each developing module holds a wafer W on, for example, a spin chuck, spreads a developer over a surface of the wafer W by pouring the developer onto the surface of the wafer W while the spin chuck holding the wafer W is rotated, removes the developer from the wafer W a predetermined after the developer has been poured onto the wafer W by pouring a cleaning liquid onto the surface of the wafer W, and dries the surface of the wafer W by rotating the spin chuck holding the wafer W at a high rotating speed. The main arms A1 and A2 of the developing blocks B1 and B2 transfer a wafer W not yet processed to the spin chucks of the developing modules of the developing blocks B1 and B2 and receives the wafer W processed by the developing process from the spin chucks, respectively.
The number of processing units, for processing a wafer W before and after processing the wafer W by the developing process, included in each of the developing blocks B1 and B2 is greater than that of the processing units of the coating block B4. Therefore, a large load is imparted on the main arms A1 and A2 that carries a wafer W to and from the processing units and the developing units. Consequently, the processing rates of the blocks B3 to B5 are controlled by the processing rates of the developing blocks B1 and B2, whereby the throughput of the resist pattern forming system may be reduced. The inventors of the present invention is making efforts to improve the throughput of the resist pattern forming system through the improvement of the throughput of the developing blocks B1 and B2.